“How many colleges and universities have a historic diner as part of their campuses?” said Karen Murray Cady, a university spokeswoman. “It’s fun, it’s useful, it’s protecting a community treasure. I think for many reasons, it was viewed as an opportunity not to be missed.”

The university purchased the diner on Loring Avenue across the street from its central campus for $600,000 last summer. The 47-seat restaurant is being operated by Chartwells, the university’s dining service vendor, and students can eat there using their meal plans. Spruced up with a just-completed upgrade, the diner otherwise has the same look and feel it has always had.

Salem State pledged to protect the diner, which was added to the National Register of Historic Places in 1999. “The intent is to keep it very much the way it has been for years,” said Cady.

An exception was a decision to add evening hours; previously it was open only for breakfast and lunch. It is now open 8 p.m. to 11 p.m. every night, in addition 6 a.m. to 3 p.m. Mondays through Saturdays and 7 a.m. to 2 p.m. Sundays.

John Hayes, resident district manager for Chartwells at Salem State, thinks the diner is a good addition to the nine other eating venues on campus.

“It’s something that is completely different,” he said, noting that students particularly seem to appreciate the opportunity to have breakfast at any time.

Hayes said the initial response has been positive. Over the three-day Martin Luther King Jr. Day weekend, “It was packed all day long,” he said, with a mixture of students and neighborhood residents.

The brisk business comes despite the fact that the facility is not yet up to full operation.

The renovations included reupholstering the seats, repainting, some new lighting, and a thorough cleaning of the premises. The oven, fryolator, and charbroiler in the back kitchen await delivery of parts needed to upgrade ventilation and fire suppression systems. Those upgrades will be made while retaining the building’s historic integrity. But there is a grill out front, and with salads and sandwiches there is still plenty left on the menu until the kitchen is in full use. That is expected in the next few weeks.

University officials have called the purchase a logical step in expanding its campus into that area. Next to the diner site is the former Weir Valves & Controls property, which Salem State bought in 2010. One of the Weir buildings houses the information technology, facilities, and mail offices. Two others are set to be razed, providing space for interim parking while a new residence hall is built.

Sterling Diner of Merrimac built the Salem Diner in 1941, and it is one of only 10
Sterling diners remaining in the state. Opened by George F. Sullivan and Frederick J. Doherty, the diner was sold in the mid-1940s to brothers James and William Kallas of Salem, according to Peter Tsoutsouras, whose late father, Theo Tsoutsouras, a first cousin of the Kallases, was the main cook in the early 1960s.

James Kallas eventually bought out his brother’s share. When he retired in 1983, he gave half the business to his son, John,
and sold the other half to Theo Tsoutsouras. In 1989, John Kallas sold his share of the business to Theo and Peter Tsoutsouras, who ran the diner until 2001, when they sold it.

The Salem Diner went through three subsequent owners. The most recent, George and Zoe Elefteriadis, bought it in 2008.

Ward 7 Councilor Joseph A. O’Keefe Sr. said residents welcome the return of the diner, which was a favorite haunt of Red Sox player, manager, and coach Johnny Pesky prior to his death in 2012.

“Everyone’s very pleased they have a place to go,” he said. “I think students are pleased because they can hang out there. It’s just some place to go rather than the traditional [campus dining venues]. It’s just a nice atmosphere.”

“It’s unique,” O’Keefe added. “What other college has a diner on campus?”

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.

Thanks & Welcome to Globe.com

You now have unlimited access for the next two weeks.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.